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Table 7 Algorithms for predicting TB among contacts based on cytokine CF responses and clinical symptoms. B. Incident TBa versus Not TBa

From: Predictive value of TNF-α, IFN-γ, and IL-10 for tuberculosis among recently exposed contacts in the United States and Canada

Characteristics

Sensitivity (%)

Specificity (%)

PPVb (%) (95% CI)b

NPVb (%)

ALL (19 incident TB, 1212 not TB)a

TNF > Median

68

49

2 (1,4)

99

INF > Median

67

51

2 (1,4)

99

IL10 > Median

61

50

2 (1,3)

99

All > Median

47

80

4 (2,7)

99

Any > Median

79

22

2 (1,3)

100

TST-

0

49

0

100

Initial TST+

79

59

3 (2,5)

99

Converter

27

92

4 (1,11)

99

TST+/Converter

100

51

3 (2,5)

100

Age < 15 years

5

89

1 (0, 5)

98

Age > = 15 years

95

11

2 (1,3)

99

TST+/Converter (19 incident TB, 595 not TB)a

TNF > Median

68

51

4 (2, 7)

98

INF > Median

50

50

3 (2, 6)

97

IL10 > Median

61

51

4 (2, 6)

98

All > Median

37

80

5 (2, 11)

97

Any > Median

74

22

3 (2, 5)

96

TST+/Converter and age < 15 years (1 incident TB, 33 not TB)a

TNF > Median

100

52

6 (0, 31)

100

INF > Median

100

53

6 (0, 32)

100

IL10 > Median

100

53

6 (0, 32)

100

All > Median

100

91

25 (1, 78)

97

Any > Median

100

18

4 (0, 20)

86

TST+/Converter and age > = 15 years (18 incident TB, 562 not TB)a

TNF > Median

67

51

4 (2, 7)

98

INF > Median

47

50

3 (1, 6)

97

IL10 > Median

59

51

4 (2, 7)

98

All > Median

33

79

5 (2, 11)

97

Any > Median

72

22

3 (2, 5)

96

Contacts with Cough (5 incident TB, 148 not TB)a

TNF > Median

80

53

5 (2, 14)

99

INF > Median

60

51

4 (1, 12)

97

IL10 > Median

60

50

4 (2, 7)

97

All > Median

40

81

7 (1, 24)

98

Any > Median

80

22

3 (1, 9)

97

Contacts with Fever or Weight Loss (1 incident TB, 68 not TB)a

TNF > Median

100

53

3 (0, 18)

100

INF > Median

100

52

3 (0, 18)

100

IL10 > Median

100

51

3 (0, 17)

100

All > Median

100

85

9 (0, 43)

100

Any > Median

100

19

2 (0, 11)

100

Contacts with Immune Compromising Conditions (10 incident TB, 844 not TB)a

TNF > Median

80

51

2 (1, 4)

99

INF > Median

89

51

2 (1, 4)

100

IL10 > Median

89

51

2 (1, 4)

100

All > Median

70

80

4 (2, 8)

100

Any > Median

90

21

1 (1, 3)

99

  1. aThe number of contacts included varies slightly from the numbers presented in the subheading for some characteristics because 14 contacts were missing TNF results (all 14 not TB), 37 contacts were missing IFN results (1 incident TB and 36 not TB), and 22 contacts were missing IL10 results (1 incident TB and 21 not TB)
  2. bIncident TB defined as TB diagnosis > 30 days after blood draw; TNF-α Tumor necrosis factor alpha, TST tuberculin skin test, TB tuberculosis; Immune Compromising Conditions = diabetes, kidney failure, cancer, chemotherapy, organ transplant, or current steroid use; CF culture filtrate, PPV positive predictive value, NPV negative predictive value, CI confidence interval